Mule - Peter Parkin & Alison Darby

Two strangers are brought together by a secret carried by a heroic
Border Collie, “Mule”. A tiny microchip opens the door to a mystery
surrounding the horrific events of 9/11. It gradually becomes clear to
the dog’s new owner that there was more behind that name. The dog has a
sinister history, being owned by a now deceased CIA agent who was
involved in the deception of 9/11, and eventually did his unsuccessful
best to come clean with his conscience – only to be silenced
permanently.

That agent left cryptic clues on the dog’s microchip, and discovered
that he himself had been used as a mule by brutal manipulators. They
deceived him into being an unwitting collaborator in a devious and
world-changing plot that, tragically, might never have its truth see the
light of day.